#pragma once

#include "index.hpp"
#include "util.hpp"
#include "log.hpp"
#include <algorithm>
#include <jsoncpp/json/json.h>

namespace ns_searcher{

  struct InvertedElemPrint{
    uint64_t doc_id;
    int weight;
    std::vector<std::string> words;
    InvertedElemPrint():doc_id(0), weight(0){}
  };

  class Searcher{
    private:
      ns_index::Index *index;
    public:
      Searcher(){}
      ~Searcher(){}
    public:
      void InitSearcher(const std::string &input)
      {
        //获取或创建index对象
        index = ns_index::Index::GetInstance();
        std::cout << "GetInstance" << std::endl;
        LOG(NORMAL, "获取index单例成功...");
        //根据index对象建立索引
        index->BuildIndex(input);
        std::cout << "Build Done" << std::endl;
      }

      //query：输入关键字；json_string：返回值
      void Search(const std::string &query, std::string *json_string)
      {
        //1.分词
        std::vector<std::string> words;
        ns_util::JiebaUtil::CutString(query, &words);
        //2.触发
        //ns_index::InvertedList inverted_list_all;
        std::vector<InvertedElemPrint> inverted_list_all;

        std::unordered_map<uint64_t, InvertedElemPrint> tokens_map;
        
        for(std::string word: words){
          boost::to_lower(word);

          ns_index::InvertedList *inverted_list = index->GetInvertedList(word);
          if(nullptr == inverted_list){
            continue;
          }

          //inverted_list_all.insert(inverted_list_all.end(), inverted_list->begin(), inverted_list->end());

          for(const auto &elem: *inverted_list){
            auto &item = tokens_map[elem.doc_id];//不存在的会新建

            item.doc_id = elem.doc_id;
            item.weight += elem.weight;
            item.words.push_back(elem.word);
          }

          for(const auto &item : tokens_map){
            inverted_list_all.push_back(std::move(item.second));
          }

        }
        //3.合并排序
        //std::sort(inverted_list_all.begin(), inverted_list_all.end(),\
        //    [](const ns_index::InvertedElem &e1, const ns_index::InvertedElem &e2){
        //    return e1.weight > e2.weight;
        //    });
        std::sort(inverted_list_all.begin(), inverted_list_all.end(),\
              [](const InvertedElemPrint &e1, const InvertedElemPrint &e2){
              return e1.weight > e2.weight;
              });

        //4.构建
        Json::Value root;
        for(auto &item : inverted_list_all){
          ns_index::DocInfo * doc = index->GetForwardIndex(item.doc_id);//通过文件id正排查找
          if(nullptr == doc){
            continue;
          }
          Json::Value elem;
          elem["title"] = doc->title;
          elem["desc"] = GetDesc(doc->content, item.words[0]);//截取content的一部分
          elem["url"] = doc->url;

          root.append(elem);
        }

        //Json::StyledWriter writer;
        Json::FastWriter writer;
        *json_string = writer.write(root);
      }

      std::string GetDesc(const std::string &html_content, const std::string &word)
      {
        const int prev_step = 50;
        const int next_step = 100;
        //1.找到关键词首次出现位置
        auto iter = std::search(html_content.begin(), html_content.end(), word.begin(), word.end(), [](int x, int y){ 
            return (std::tolower(x) == std::tolower(y)); 
            });
        if(iter == html_content.end()){
          return "None";
        }
        int pos = std::distance(html_content.begin(), iter);
        //2.获取摘要范围
        int start = 0;
        int end = html_content.size() - 1;

        if(pos > start + prev_step) start = pos - prev_step;
        if(pos < (end - next_step)) end = pos + next_step;

        //3.截取子串
        if(start >= end) return "None";
        std::string desc = html_content.substr(start, end - start);
        desc += "...";
        return desc;
      }
  };


}








































